This invention relates generally to battery driven electronic wristwatches. In the art, electronic wristwatches are generally provided with a crystal vibrator, the natural oscillation frequency of the vibrator providing a time standard signal. The time standard signal is converted into suitable timekeeping signals through the use of an C-MOS (complimentary coupled metal oxide semiconductor) integrated circuit including a divider circuit, a counter circuit, a decoder circuit, a driver circuit and other related circuitry. The timekeeping signals are generally applied to a display device such as a liquid crystal display to provide a visual time indication. In the art, the battery generally utilized is a silver battery having a voltage range from 1.4 volts to 1.6 volts. Such silver batteries have a capacity in the range of 100 milliampere-hours to 150 milliampere-hours and a life of between two and three years. However, in recent years, watch designers have demanded the utilization of this batteries to increase the aesthetic appeal of the watch and have further demanded increased battery life to increase the utility of the electronic wristwatches. In order to meet these demands, several approaches have been proposed including the use of solar batteries to supplement the permanent battery to reduce the drain on the permanent battery, and the use of high density batteries such as the lithium battery. However, although the lithium battery has several times as much capacity as a conventional silver battery, the lithium battery has a disadvantage in that its power consumption is twice as large as that of a silver battery operating the same circuitry. This results because the voltage output of a lithium battery is about 2.8 volts.
What is needed is an electronic timepiece capable of using a high voltage battery such as a lithium battery without excessive power consumption.